diff --git a/openedx/core/djangoapps/credit/email_utils.py b/openedx/core/djangoapps/credit/email_utils.py
index 99670b0634..a674e3edb8 100644
--- a/openedx/core/djangoapps/credit/email_utils.py
+++ b/openedx/core/djangoapps/credit/email_utils.py
@@ -125,7 +125,7 @@ def send_credit_notifications(username, course_key):
     to_address = user.email
 
     # send the root email message
-    msg = EmailMessage(subject, None, from_address, [to_address])
+    msg = EmailMessage(subject, '', from_address, [to_address])
     msg.attach(notification_msg)
     msg.send()
 
diff --git a/openedx/core/lib/api/tests/test_authentication.py b/openedx/core/lib/api/tests/test_authentication.py
index a5f5049294..b4d91469ee 100644
--- a/openedx/core/lib/api/tests/test_authentication.py
+++ b/openedx/core/lib/api/tests/test_authentication.py
@@ -18,6 +18,7 @@ from django.conf.urls import include, url
 from django.contrib.auth.models import User
 from django.http import HttpResponse
 from django.test import TestCase
+from django.test.utils import override_settings
 from django.utils.http import urlencode
 from nose.plugins.attrib import attr
 from oauth2_provider import models as dot_models
@@ -76,10 +77,9 @@ urlpatterns = [
 @ddt.ddt
 @unittest.skipUnless(settings.FEATURES.get("ENABLE_OAUTH2_PROVIDER"), "OAuth2 not enabled")
 @pytest.mark.django111_expected_failure
+@override_settings(ROOT_URLCONF=__name__)
 class OAuth2Tests(TestCase):
     """OAuth 2.0 authentication"""
-    urls = 'openedx.core.lib.api.tests.test_authentication'
-
     def setUp(self):
         super(OAuth2Tests, self).setUp()
         self.dop_adapter = adapters.DOPAdapter()